Which STI (Sexually Transmitted Infection) tests should be repeated at 3 months after sexual assault?

STI Testing at 3 Months After Sexual Assault

At 3 months after sexual assault, HIV testing should be repeated, along with serologic tests for syphilis if initial test results were negative. 1

Recommended STI Testing Timeline After Sexual Assault

Initial Examination

• Cultures or nucleic acid amplification tests for:
  • Neisseria gonorrhoeae
  • Chlamydia trachomatis
• Wet mount and culture for Trichomonas vaginalis
• Baseline serologic testing for:
  • HIV
  • Hepatitis B
  • Syphilis

1-2 Week Follow-up

• Review initial test results
• Ensure treatment was provided if needed
• Arrange follow-up for any infections

2-Week Follow-up (if initial tests were negative and no prophylaxis given)

• Repeat STI testing to detect infections that may not have been detectable at initial examination
• For those who received prophylactic treatment, post-treatment testing only if symptoms develop

3-Month Follow-up

• HIV testing - using methods to identify acute HIV infection 1
• Syphilis serologic testing - if initial results were negative 1

Rationale for 3-Month Testing

The 3-month timeframe is critical because:

1. Window period for seroconversion: HIV antibodies typically develop within 3 months after infection, making this an appropriate time for definitive testing 1

2. Late manifestations: Some STIs, particularly HIV and syphilis, may not be detectable immediately after exposure but become detectable by 3 months 1

3. Risk assessment: While HIV transmission from a single sexual assault is relatively rare, specific circumstances such as trauma, bleeding, or ejaculation can increase risk 1

Important Considerations

• Completion of vaccination series: The 3-month visit provides an opportunity to continue hepatitis B vaccination if initiated at the initial examination 1

• Adherence challenges: Follow-up compliance can be challenging for sexual assault survivors, making each visit an important opportunity for comprehensive care 1

• Risk stratification: Recent research shows that no new cases of hepatitis B, hepatitis C, HIV, or syphilis were diagnosed at 3-month follow-up in one cohort study, but testing remains important for high-risk exposures 2

• Treatment verification: For those who received prophylaxis, the 3-month visit confirms treatment effectiveness 1

Common Pitfalls to Avoid

• Missing follow-up opportunities: Only about 45-46% of sexual assault survivors return for follow-up testing 3, so emphasize the importance of the 3-month visit

• Neglecting hepatitis B testing: Complete the vaccination series if initiated at the initial visit 1, 4

• Focusing only on bacterial STIs: While bacterial STIs are more common, viral STIs like HIV require longer follow-up periods 1

• Overlooking psychological support: The 3-month visit is also an opportunity to assess psychological healing and provide ongoing support

By following this testing protocol, clinicians can ensure appropriate detection and management of STIs acquired during sexual assault, minimizing long-term morbidity and mortality for survivors.